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suggestion for selection of suitable DSP

Dear sir,

Please suggest a suitable DSP with FFT accelerator.

Our requirement is to process a vibration signal of frequencies upto 5KHz.

Sample frequency of the signal is 15KHz.

We need DSP processor, which has ADC module inbuilt for sampling, and a FFT accelerator for online processing of FFT algorithm.

Please let us know the cost of suitable development boards if any for suggested DSP.



Thanks in advance

Raghu K

  • Hi Raghu,

    Apologies for the delay in getting back to you.

    Our ADSP-214xx family of processors have FFT Accelerator and these processors can satisfy your sampling frequency requirements.

    But this does not have an inbuilt ADC module. You will have to use an external ADC (or CODEC) and interface it with the ADSP-214xx processor.

    The link to ADSP-21489 datasheet and Evaluation platform is given below.

    The eval board has a codec AD1939 connected to ADSP-21489. We have a lot of Audio Talkthrough example codes which will get you started.

    In fact we have an example code where we use the IIR accelerator for processing the real-time data and this is integrated to the Audio Talkthrough code.

    Go through the datasheet of ADSP-21489 and the data of codec AD1939 and see if this satisfies your requirements



  • Hello Raghu,

    I support the audio CODEC products so I have a few questions and suggestions. How many channels of ADC do you need? Do you need any DACs?

    The AD1974 is the version of the AD1939 family with only four ADCs.

    Then there is the ADAU1977 and ADAU1979 which has advanced microphone interfacing features and it is also a 4 channel ADC.

    If you need fewer channel then the ADAU1961 is a stereo version with two ADCs and two DACs. They all will go down to a 15 kHz sampling rate.


    Dave T

  • There are many different possible answers to the original post. It it certainly much easier to do FFTs with a floating point DSP than with a fixed point processor. Any of the 4th generation SHARCs (2146x, 2148x or 2147x) will probably work well whether you use the accelerator or the core for the processing.

    You haven't stated the size of the FFT, number of channels, power requirements, external interface requirements, etc

    The answers to these questions may have a big impact on the best fit for your situation


    The question is a little like, I need a car, what should I buy or how big should the engine be?

    We have many SHARC based solutions with data converters. We even have boards / instruments aimed specifically for vibration measurement.

    Al Clark

  • Hi Clark,

    We need 3 channels of  Single axis vibration sensors with an acoustic sound input and Voltage and Current sensing application, do you have a solution for Vibration and acoustics?